Authement started his career at the Calcasieu Parish Sheriff's Office in 1989, under Sheriff Wayne McElveen as a patrol officer. In 1997, he moved to the Ward 3 Marshal's Office under then-Marshal Tony Mancuso and became a supervisor of the city jail and the warrants division, and served as a member of the Calcasieu Parish Violent Crimes Task Force.

From July - November 2004, Authement served as interim Ward 3-City Marshal when Mancuso was elected sheriff. He moved back to the Sheriff's Office to become Commander of Law Enforcement Centers and Misdemeanor Investigations in December 2004.

Authement also served in the U. S. Navy during the Viet Nam era. During his law enforcement career, Authement graduated from the Calcasieu Parish Regional Law Enforcement Academy and served as president of the graduating class. He has attended several law enforcement training courses with an emphasis on supervision and leadership. He also belongs to several local civic organizations.